Apparatus for purifying talc and the like



Nov. 10, 1.925. 1,560,910

G. F. HANNAM APPARATUS FOR PURIFYING- TALC AND THE LIKE Filed June 9'.22 /6- lll-4wl/Ill/llll/rl/l/r//ll111Awill', A

Patented Nom i6, i925.

GEORGE F. HAMMAM, F LOS ANGELEQ, CALlFORNA., ASSIGNOROF TWOeTHRDS 'IOninos n. nnuvvoafrnr nun on' Lann, cresson.

T GERGE FBGFET, JR., BOTH 0F PORT- APPARATUS EUR P'URIIFYNG TAL() ANDTHE LIKE.

Application filed [fune 9,

T 0 all whom t may concern."

lie it known that ll, GEORGE F. HANNAM, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented new and usefull improvements in Apparatus forlPurifying Tale and the like, of which the following is a specification.

rlfhe present invention relates to a method for the pneumatic screeningof talc and other finely powdered or line grained materials, and has forits object particularly to provide an apparatus and method for thetreatment of talc so as to eifectually remove from the same any grit andother impurities that might be contained in the same.

A further object is to provide for the effective separation of theimpurities and grit by operation of a pneumatic apparatus wherein thematerial is rapidly treated to the action of a current of air both underpressure and under suction, and is directed through screens effecting asubdivision of the particles of the talc according to size.

Other objects will be made manifest in the following specication of anembodiment of the invention illustrated in the accompany* ing drawings,in which- Figure 1 is a vertical longitudinal section substantiallyalong the center of the apparatus.

Fig. 2 is a horizontal section on the line 2-2 of Fig. 1. y

It is known that talc bearing material as obtained from its naturalsource is mixed with varying quantities of calcium carbonate, alkalineimpurities, and grit of other character, and it is also known that thepure talc particles which are free of impure association have adifferent coefficient of friction from those particles impregnated withimpurities, and by the present apparatus the pure talc particles areseparated from the impure particles by treatment of the material to acurrent of air in which the pure talc particles are carried by reason oftheir different characters beyond a Zone in which the impure particlesand the nontalc bearing particles are deposited.

ln its present embodiment, the apparatus consists of a substantiallyoblong housing 2 of suitable dimensions and including closed ends 3 andl and the closed top 5. rlhe housing has a bottom 6 and a series oftranverse,

1922. serial No. 567,062.

vertical screens 7, 8 and 9 constituting separa-ting walls.

it one en d of the housing there is provided a vertical compartment 10which may project down below the bottom 6 and is provided with an outletgate 11 in a vertical wall. Extending upwardly into the bottom of thecompartment 10 there is a blow pipe 1,2 connected to a blower 13 whichis pros vided with a suction pipe 14 extended to a source of supply (notshown) of material to be treated.

rlhe compartment 10 extends up through the bottom 6 and has at one sidea vertically adjustable gate or valve 15.` The blow pipe l2 extends well`up in the compartment 10 and terminates adjacent to the top of thecompartment. The blower being started, the finely floured or pulverizedmaterial, such as talc, to be treated is blown into the compartment 10,and because of the greater .speciiic gravity of impurities and of largerfragments of talc, these will tend to settle back immediately in thecompartment 10, while the latter and smaller particles 0f talc, bothbecause of their low weight and also because of their low coefficient offriction, will be carried by the air discharged from the blow pipe 12through the opening above the gate or valve 15 into the firstcompartment 16 formed between the end wall 3 and the first screenpartition 7 in the housing. The bottom of the compartment 16 is inclineddownwardly to a discharge hopper 17. To facilitate the flow of thecurrent of air through the chamber in the housing and through thepartitions 7,8 and 9,a suction fan 18 is connected by a suction pipe 20to the top of chamber 21 being the last of the series of chambers formedbetween the screens 7, 8 and 9.

It is found by the practice of the present method that the heavierimpurities and the heavier' fragments of talc and fragments of talccontaining impurities will fall back into the grit collectingcompartment 10 from which they may be discharged, as 'occasion requires,through the outlet gate 11. The pure particles of talc freely float intothe chamber 16 and certain of the particles according to their weightwill drop therein, while other particles will pass through the screen 7and fall to the hopper 7 thereof; other particles will pass through thescreen 8 and fall into the hopper 8 oit its chamber,x and the very fineparticles will pass through screen 9 into the iiual collecting chamber2l which is provided with a transverse sereen 22 below the suction mouthof the pipe 20. lt is round that the air drawn by the suetion fau 18 issubstantialh7 iti-ee from tale or other particles, and that all ofthetale particles eolleetetl in the several hoppers l?, 7 and 8 are about@Q1/2% pure.

Considering a given quantity ot material to be treated, about 33% oi thewhole is eolleetetl in the grit an-:l dirt receiving; compartment lO,while the remaining portion passes into the pure tale Collecting'hopper.

The rate oit l'iou' oit the materiai being; treated` can regulated by anadjustment ot the gate l5.

Various nxorliiieations and changes may he retorted to Within the spiritot the iuvention as claimed.

lli/'hat is elaiifnetl is:

l. ln an apparatus for the treatment or pulverized tale bearingmaterial, a horizontal housingy provided with a plurality otsubstarrt-rallyv vertical ehambers Whose Walls are formed ot screenmaterial, means oomprising a blower and a suction fan ifor esrerizet'ihousingy i* v with a ivurality o'l suh stantially .fertiefal eliamla-,lwhos( )arating` Walls are At'ormezl ot screen material., hihi-11g aCirculation ot air the limiting' to the other s, said homing having anovitled with an atlt valve :mtl in which the im- "tll :ui-l troni Wiiehthe pure pare carried in the moving stream ei fulating means consistingfr which Yreeds the material into the at one end, and a suction tan 'fordrawing air from the opposite end of the housine.

ln testimony whereof l have signed my name to this specification.

GEO. l?. HANNAM.

